Timepiece escapement lever

ABSTRACT

An escapement lever for a timepiece comprises a lever body including at one end a pair of divergent arms each carrying a pallet or pallet pin. The body is mounted on an arbor for oscillation with the pallets or pins cooperative with a toothed escapement wheel. The pallets or the pallet pins are coated with hard metal to increase wear, reduce fruction and to facilitate lubrication.

States Patent 1 {111 3,73,11

Simon-Vermot [4 June 12, 1973 TIMEPIECE ESCAPEMENT LEVER [75] Inventor:Andre Simon-Vermot, 2400 Le [56] References Cited Locle, SwitzerlandUNITED STATES PATENTS [73] Assignee: Les Fabriques dAssortiments 32 28?:4 13% g g 5%? 0 en e a g f 'gf gg Neuchatel 3,511,340 5/1970Simon-Vermot 58/121 A Filed! P 1972 Primary ExaminerStephen J. Tomsky[21] App! No; 290 828 Assistant Examiner-U. Weldon v Attorney-Dwitht H.Smiley Related US. Application Data [63] ggtntgigataicgng-lnggrt of Ser.No. 52,093, July 2, 1970, [57] ABSTRACT i An escapement lever for atimepiece comprises a lever body including at one end a pair ofdivergent arms each [30] J l Fnreign Applufauon Priority Data carrying apallet or pallet pin. The body is mounted on U y 1969 Switzerland10608/69 an arbor for oscillation with the pallets or p p tive with atoothed escapement wheel. The pallets or [2?] 58/116 the pallet pins arecoated with hard metal to increase E Q i 6 R wear, reduce fraction andto facilitate lubrication.

12 Claims, 6 Drawing Figures PATENIH] JUN I 2 I915 i i/ i TIMEPIECEESCAPEMENT LEVER CROSS-REFERENCE TO RELATED APPLICATION This applicationis a continuation-in-part of Application Ser. No. 52,093, filed July 2,1970, now US. Pat. No. 3,694,885.

BACKGROUND OF THE INVENTION The usual escapement lever in a timepiecemechanism or movement comprises a metallic body secured to an arboradapted for oscillation and having a pair of divergent arms each ofwhich carries a pallet or a pin for cooperative engagement with theteeth of like radial projections of an escapement wheel. lf pallets areemployed, jewels, such as rubies, usually are mounted thereon to resistfrictional wear but, in any event, it is difficult to maintainlubrication either of the jewels or the metal as in the case of pins.

SUMMARY OF THE INVENTION An escapement lever according to the presentinvention comprises a metal lever body, preferably having a safety pinat one end, the other end of which terminates in a pair of divergentarms respectively supporting a pallet or a pallet pin. The pallets orpins and, conveniently, the lever body, are coated with a hard metalsuch as electroless nickel, electroless chrome or a hard alloy such ascobalt-rhenium alloy, which has a low coefficient of friction and towhich a lubricating oil of the type, for example, known as Synt-A-Lube,readily adheres. The escapement lever, including the safety pin andpallets may be stamped from a metal plate which then is coated with thehard metal or individually coated pallets or pins may be mounted on alever body.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an escapementlever comprising pallets integrally formed therewith;

FIG. 2 is a cross-sectional view taken on line 2-2 of FIG. 1;

FIG. 3 is a fragmentary plan view of a modified lever with individuallysupported pallets;

FIG. 4 is an enlarged fragmentary cross-sectional view taken on line 4-4of FIG. 3;

FIG. 5 is a fragmentary plan view of an escapement lever having palletpins, and

FIG. 6 is an enlarged fragmentary cross-sectional view taken on line 6-6of FIG. 5.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawing,specifically to FIG. 1, an escapement lever for a timepiece movement, inaccordance with the present invention, comprises a lever 10 of elongatedconfiguration having at one end a safety pin 12 and at the other end apair of divergent arms 14, 14 respectively disposed on opposite sides ofthe longitudinal centerline of the'lever, each carrying a pallet 16,16'. The lever 10 is provided substantially on its longitudinalcenterline with a bore 18 to receive an arbor 20 by which the lever ismounted for oscilla- I tion with respect to an escapement wheel, notshown.

According to the invention, the lever shown in FIG. 1 comprises a metalbody which may be coated by a layer 24 of hard metal. The body may beblanked from any suitable metal such as brass, german silver, an alloyof one-third each of Cu, Ni and Mn, or steel, either before or aftercoating, and the hard metal preferably comprises electroless nickel, analloy of nickel and phosphorus containing from about 3.5 to 11.5 percentof phosphorus, the rest of the composition being constituted by nickel.

The lever body is subjected to a finishing operation to impart coldrolled properties thereto and provide a hardness of about 600 HV(hardness in the Vickers scale). If desired, the lever may be subjectedto heat treatment to increase the hardness by precipitation of a phase.For the foregoing purposes, to increase the hardness up to about 800 HV,the lever may be subjected for about one hour at 600C or for about 10hours at 260C.

After such heat treatment the coating has a coefficient of friction ofabout 0.2 and after this coating, for example, the area of the palletsl6, 16, has been lubricated, the coefficient friction is reduced toabout 0.008. The electroless nickel is chemically deposited by dippingthe lever body in a suitable bath to obtain a coating having a thicknessof preferably less than t. Further, it is possible to coat theescapement lever by electroless nickel, e.g. by introducing the piece ina bath such as Enplate No. 415 or Niklad 792. The cold rolling effectproduced by the finishing operation establishes a greater adhesionbetween the coating and the metal of the body.

Alternatively, the hard metal may comprise electroless chrome or a hardalloy such as a cobalt-rhenium alloy. A suitable bath may compriseDuralloy to form a coating of electroless chrome or a bath composed of60 g/l of cobalt sulfat (C080 7 H 0), 66 g/l/ of citric acid (COOH) CHC(OH) (COOH) CH COOH, 10 to 30 g/l of perrhrenate of potassium (K-Re0,)and about 10 g/l of perrhrenate of ammonium (NH -ReO as regenerator, toform a coating of an alloy of cobalt and rhenium. In the latter bath thedensity of of current should be 2 to 12 Ampldm the pH about 7.6 and thetemperature about C. Such coatings may be subjected to the finishingoperations.

According to embodiments of the invention, the pallet members, whetherpallets having substantial flat operative surfaces or pins havingcylindrical surfaces, may be produced separately, at least theiroperative surfaces coated with the hard metal, and fixed to the lever.For example, as shown in FIGS. 3 and 4, a lever 10a may have arms 14a,14a divergent from an arbor 20a. The arms may have their extremities inthe form of jaws defining slots 26, 26 within which are fitted pallets16a, 16a, respectively, and which may be secured by any suitable bondingsuch as solder or adhesive. The pallets may comprise metal bodies 28completely covered with a coating 30 of the hard metal or the coatingmay be limited to the operative surfaces of the pallets, that is thosesurfaces which operatively engage the escapement wheel.

Similarly, as shown in FIGS. 5 and 6, pins may be substituted forpallets. In this embodiment, a lever 10b has arms 14b, 14b divergentfrom an arbor 20b and the extremities of the arms have bores 32, 32'respectively carrying pins 16b, 16b which may comprise bodies 34 havinga hard metal coating 36. Obviously, the pins may be suitably bonded inthe bores. The coating of the individual pallet members, whether palletsor pins, may be effected in the same manner as previously described andthe coatings have the same characteristics as previously described.Moreover, the pallet members may be fixed to the levers prior to coatingand thereafter both the lever and pallet members coated.

1 claim:

1. A timepiece escapement lever comprising a lever body having alongitudinal centerline and an oscillator axis substantiallyintersecting said centerline,

a pair of pallet members carried by said body on opposite sides of saidcenterline and having operative surfaces for cooperative engagement withan escapement wheel,

coatings of hard metal on at least said operative surfaces of saidpallet member, and said hard metal being from the group consisting ofelectroless nickel, electroless chrome and cobalt-rhenium alloy.

2. A lever according to claim 1 wherein said coating has a hardness ofabout 600 to 800 HV.

3. A lever according to claim 2 wherein said coating has a thickness ofnot more than 50 u.

4. A lever according to claim 3 wherein said electroless nickel is analloy of nickel and phosphorous, containing 3.5 to 11,5 percentphosphorus, the rest being nickel.

S. A lever according to claim 1 wherein said coating has a thickness ofnot more than 50 .1..

6. A lever according to claim 5 wherein said electroless nickel is analloy of nickel and phosphorus, containing 3.5 to 11.5 phosphorus, therest being nickel.

7. A lever according to claim 1 wherein said electroless nickel is analloy of ,nickel and phosphorus, c0ntaining 3.5 to 11.5 percentphosphorus, the rest being nickel.

8. A lever according to claim 1 wherein said pallet members comprisepallets.

9. A lever according to claim 8 wherein said pallets are integral withsaid lever body.

10. A lever according to claim 9 wherein said pallets are at one end ofsaid lever body, an integral safety pin, lever body and pallets.

11. A lever according to claim 10 wherein said coating has a hardness ofabout 600 to 800 HV and a thickness of not more than 50 u, and comprisesan alloy of 3.5 to 11.5 percent phosphorus with the rest being nickel.

12. A lever according to claim 1 wherein said pallet members are pins.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION June 12 1973Patent No. 3 1 738,101 Dated Inventor) Andre Simon-Vermot It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the Foreign Application. Priority Data:

Change the Swiss number to 10607/69 Signed and sealed this 16th day ofJuly 1974.

- (SEAL) Attest:

McCOY M. GIBSON, JR C. MARSHALL DANN Attesting Officer CommissionerofPatents USCOMM-DC 60376-P69 U.S, GOVERNMENT PR NTING OFFICE: 19690-366-334 FORM PO-IOSO (10-69) UNITED STATES PATENT OFFICE CERTIFICATEOF CORRECTION patent 3,738,101 Dated June 12, 1973 Invent r( AndreSimon-Vermot It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

In the Foreign Application. Priority Data:

Change the Swiss number to 10607/69 Signed and sealed this 16th day ofJuly 1974.

;(SEAL) Attest:

MCCOY M. GIBSON, JR C. MARSHALL DANN Attesting Officer CommissionerofPatents FORM 1 0-1050 (10-69) uscoMM-Dc 60376-P69 fi U.S1 GOVERNMENTPRINTING OFFICE: I969 0-366-334

1. A timepiece escapement lever comprising a lever body having alongitudinal centerline and an oscillator axis substantiallyintersecting said centerline, a pair of pallet members carried by saidbody on opposite sides of said centerline and having operative surfacesfor cooperative engagement with an escapement wheel, coatings of hardmetal on at least said operative surfaces of said pallet member, andsaid hard metal being from the group consisting of electroless nickel,electroless chrome and cobalt-rhenium alloy.
 2. A lever according toclaim 1 wherein said coating has a hardness of about 600* to 800* HV. 3.A lever according to claim 2 wherein said coating has a thickness of notmore than 50 Mu .
 4. A lever according to claim 3 wherein saidelectroless nickel is an alloy of nickel and phosphorous, containing 3.5to 11.5 percent phosphorus, the rest being nickel.
 5. A lever accordingto claim 1 wherein said coating has a thickness of not more than 50 Mu .6. A lever according to claim 5 wherein said electroless nickel is analloy of nickel and phosphorus, containing 3.5 to 11.5 phosphorus, therest being nickel.
 7. A lever according to claim 1 wherein saidelectroless nickel is an alloy of nickel and phosphorus, containing 3.5to 11.5 percent phosphorus, the rest being nickel.
 8. A lever accordingto claim 1 wherein said pallet members comprise pallets.
 9. A leveraccording to claim 8 wherein said pallets are integral with said leverbody.
 10. A lever according to claim 9 wherein said pallets are at oneend of said lever body, an integral safety pin, lever body and pallets.11. A lever according to claim 10 wherein said coating has a hardness ofabout 600* to 800* HV and a thickness of not more than 50 Mu , andcomprises an alloy of 3.5 to 11.5 percent phosphorus with the rest beingnickel.
 12. A lever according to claim 1 wherein said pallet members arepins.
 12. A lever accordingo claim 1hereinsaid pallet membersre pins.